Don't bother learning jQuery today if you aren't already familiar with it.
If you want to be productive as soon as possible, pick React or Vue and stick with them until you can make something useful, following the respective best practices.
If you want to learn about the web platform, don't use jQuery, use what's already natively available in the browsers. That includes the vast majority of what jQuery originally was meant to solve (from fetch() for ajax to document.querySelectorAll('*').forEach(x=>a=x.classList.add('new-class')) for $('*').addClass('new-class'))